Philly flirts with a temperature record at the freeze-resistant airport

While temperatures dropped into the 20s elsewhere in the region early Wednesday, including Atlantic City, the blossoms and blooms in Philly evidently benefited from some unnatural protection.

The official temperature at Philadelphia International Airport did not make it below 33 degrees, the National Weather Service reported, and it’s highly likely that the city is going to see its second-earliest last freeze of the season in 150 years of record-keeping.

What happened to the freeze?

“It really boils down to the urban heat island,” said Alex Staarmann, the climate specialist at the weather service office in Mount Holly, adding that readings at several other stations around the city failed to get below 32.

All those sun-soaking buildings and hard surfaces that are reluctant to yield their heat at night create heat islands in urbanized areas, and Philadelphia is part of an archipelago of such islands along the I-95 corridor.

Those effects notwithstanding, meteorologists and the marvelous machines they consult had foreseen temperatures falling into the upper 20s even at PHL. They dropped to 27 degrees at the Wilmington airport and 29 at Atlantic City’s.

Some of those spectacular blooms on the older magnolia trees lost some of their glory, said arborist Jason Parker, district manager with the Davey Tree Expert Co., in Warminster, Bucks County.

The temperature did get to 30 degrees at Northeast Philadelphia Airport, but the fact that it didn’t get that low at its bigger cousin by the Delaware River “was definitely surprising,” Staarmann said.

No flirtations with freezing are in the forecast at least through Tuesday, and it is likely that Philly will stay in second place for the earliest last freeze.

The most-recent below-freezing reading occurred on March 9, when it fell to 30 degrees.

The record for the earliest final-freeze occurrence is March 8, set in 2020, followed by March 11, 1953.

After a day when winds gusts and temperatures were in the 40s, Wednesday was milder with highs in the low 50s and less wind.

Of note, Tuesday broke Philly’s eight-day streak of measurable rain, but significantly more is on the way, Staarmann said.

Rain is possible from Thursday afternoon into Friday night and perhaps into Saturday, with one to two inches possible, he said.

In the 60-day period that ended Tuesday, rainfall was significantly above normal in Philly and all seven of the neighboring counties in Pennsylvania and New Jersey.

But the region remains under drought advisories, the result of a historically dry September and October during which an official total of 0.77 inches of rain was measured in Philly. Parker said the trees are going to be feeling the stresses for a while.

“That’s going to have some serious impacts as the year goes on,” he said.

Plus, blustery winds have subjected the trees and foliage to rapid drying cycles that “really dried stuff out, especially the evergreens. We’ve only seen a fraction of the damage,” he said.

An Inquirer analysis of the Jan. 1-to-March 20 period found that gusts reached 35 mph or higher on 26 of those days — including four with gusts of 50 mph or more. That was more than in any Jan. 1-March 20 period in at least the last 20 years.

As welcome as the additional precipitation may be this week, the rains likely will all but end the magnolia show of 2025, Parker said.

Still, he said, the magnolias have had a good run, showing off for a good 10 days around the region. “Normally,” he said, “we get about a week.”